Effects of biogas residue addition, as cultivation substrate, on ginseng growth

Abstract

Energy shortages have become a major concern for people. With the advancements in science and technology, crop yields are increasing, and more crop straw is being produced. The annual straw production in China is approximately 700 million tons (Lin et al. 2022). In addition to being used as a substrate, fertiliser, fuel, animal feed and raw material, approximately 15% of the water is still unused (Zhou et al. 2023). The problem of environmental pollution caused by excess straw poses a serious threat to human health and has become a global problem that urgently needs to be solved. Straw energy conversion, such as converting straw into biogas through anaerobic fermentation, is one of the most effective ways to address residual straw pollution.During convergence, the production continuity determines that the emitted biogas residue is charac-terised by continuous, large amounts and incomplete material decomposition. Therefore, searching for efficient, convenient and low-cost methods is necessary to eliminate the subsequent pollution pressure caused by a large amount of excess biogas residue. Composting is a way to convert biogas residues into usable resources effectively. During the composting process, the undecomposed materials in the digestate are further degraded by microorganisms, and potential threats such as parasites, pathogens and weeds are significantly reduced (Bernal et al. 2009). Mature biogas residue compost has been used as a growing substrate for a variety of crops, such as zucchini, pepper, eggplant, lettuce, and tomato plants (Jara Samaniego et al. 2017, Meng et al. 2018, Liu et al. 2023a). However, perennial plants, particularly perennial medicinal plants, have rarely been reported.